[1.4.x] Fixed #17976 -- Made forms.BooleanField pickleable.

Backport of 9350d1d59c1a4e6a9ac246a808f55da35de0df69 from master.

This was a regression in Django 1.4.
Thanks bronger for the report and claudep for the patch.

1 files changed, 7 insertions, 4 deletions

diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 1fbef98deb..4813af69e9 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -487,15 +487,18 @@ class TimeInput(Input):
             pass
         return super(TimeInput, self)._has_changed(self._format_value(initial), data)
 
+
+# Defined at module level so that CheckboxInput is picklable (#17976)
+def boolean_check(v):
+    return not (v is False or v is None or v == '')
+
+
 class CheckboxInput(Widget):
     def __init__(self, attrs=None, check_test=None):
         super(CheckboxInput, self).__init__(attrs)
         # check_test is a callable that takes a value and returns True
         # if the checkbox should be checked for that value.
-        if check_test is None:
-            self.check_test = lambda v: not (v is False or v is None or v == '')
-        else:
-            self.check_test = check_test
+        self.check_test = boolean_check if check_test is None else check_test
 
     def render(self, name, value, attrs=None):
         final_attrs = self.build_attrs(attrs, type='checkbox', name=name)